With reference to FIG. 1, a multilayer ceramic capacitor 1 that is a representative example of a multilayer ceramic electronic component according to the present invention will be described first.
Multilayer ceramic capacitor 1 includes a multilayer body 2 which is formed of a plurality of laminated ceramic layers 3 and a plurality of internal electrodes 4 and 5 each formed along an interface between ceramic layers 3.
A first external electrode 8 and a second external electrode 9 are formed at mutually different positions on an outer surface of multilayer body 2. In the multilayer ceramic capacitor 1 illustrated in FIG. 1, first external electrode 8 and second external electrode 9 are formed respectively on opposing end surfaces 6 and 7 of multilayer body 2. Internal electrode 4 includes a plurality of first internal electrodes 4 which are electrically connected to first external electrode 8, and internal electrode 5 includes a plurality of second internal electrodes 5 which are electrically connected to second external electrode 9. First internal electrodes 4 and second internal electrodes 5 are disposed alternately in the lamination direction. If necessary, a surface of external electrode 8 is coated with a first plating layer 10 and a second plating layer 12, while a surface of external electrode 9 is coated with a first plating layer 11 and a second plating layer 13.
Since size reduction is particularly required for the multilayer ceramic capacitor, the process of manufacturing the multilayer ceramic capacitor includes a method of laminating a green sheet made of a dielectric ceramic and an internal electrode layer and then sintering the laminated sheet and layer at the same time. For cost reduction, base metals such as Ni are used for an internal electrode of the multilayer ceramic capacitor.
In recent years, as thinning of the ceramic layer has further progressed, thinning of the internal electrode is also urgently required. However, thinning of the internal electrode causes a problem that the rate of coverage of the internal electrode tends to be decreased due to spherically-agglomerated metal particles. This requires sintering at a lower temperature.
Furthermore, since a multilayer ceramic electronic component is required to have various characteristics, it also becomes necessary to use various types of metals such as Ag and Cu as a metal for an internal electrode. This also requires sintering at a low temperature.
For the reasons as described above, a ceramic material that can be sintered at a low temperature and exhibits excellent dielectric properties is demanded.
For example, PTD 1 discloses a barium titanate-based dielectric ceramic composition suitable for a multilayer substrate or a multilayer ceramic capacitor, and also discloses that the dielectric ceramic composition can be sintered at 1000° C. or lower.